Search

Understanding how paleomagnetic and rock magnetic properties vary as a function of time and space is important for acquiring reliable information about the past Earth’s magnetic field. In basalts the magnetic properties are controlled by Fe-Ti oxides precipitating from the magma. The fraction, type, and mineral and magnetic grain size and shape are determined by a complicated multiphase process through the history of the lava or tephra. The deep magmatic conditions with melt composition, temperature, pressure, and oxygen fugacity are the starting point influencing the initial magnetic mineralogy and the matrix surrounding it. The final stage of crystallization is controlled also by syn-eruptive and emplacement conditions such as viscosity, cooling rate, incorporation of water, eruption style and atmospheric oxidation. Lastly, regardless of the natural environment the magnetic mineralogy is bound to further suffer from some degree of chemical alteration and low temperature oxidation. Therefore, the magnetic properties vary considerably even within the same cooling unit, and where one samples can affect the successfulness of paleomagnetic or paleointensity study. Historical eruptions like Fagradalsfjall 2021 and 2022 provide ideal locations for case studies since we know exactly not only the direction and strength of the magnetic field, but also the geochemical properties of the lavas due to near real time analysis of the eruption products. Here we present the magnetic properties of the Fagradalsfjall 2021 and 2022 eruption products. We collected samples during the eruptions as a function of time from the fast cooled materials, such as samples from the naturally fast cooled flow tops, manually quenched samples from the molten lava, and tephra. After eruptions seized and it was safe to work on the lava, we drilled over 100 lava samples from various locations and morphologies. These samples were subjected to a battery of measurements possible at University of Iceland Paleomagnetism Laboratory slightly varying depending on the type of sample such as bulk susceptibility, low field susceptibility vs temperature, hysteresis properties, backfield coercivity distribution, First Order Reversal Curves, alternating field, and thermal demagnetization. With our preliminary results we show how the magnetic properties vary a) between different types of volcanic products, b) across the lava fields and their multiple morphologies, c) as a function of depth, and d) as a function of time from the beginning of the eruption for the rapidly quenched materials.

Introduction Clinical preventive services can reduce mortality and morbidity, but Americans receive only half of the recommended care. Although wellness visits protect time for clinicians to review needs and discuss care with patients, studies have not shown that having a wellness visit improves health outcomes. This study seeks to understand the types of discussions and volume of care delivered during wellness visits. Methods Using a sample of 1,008 patients scheduled for a wellness visit from 22 primary care clinicians across 3 states from 2018 to 2019, electronic health records were reviewed, and a subset of visits was audio recorded. The discussion and delivery of clinical preventive services, as recommended by the U.S. Preventive Services Task Force, were measured, and new diagnoses were identified from the clinical preventive services. Analyses were completed in 2020. Results Even though patients were up to date with 80% of the recommended clinical preventive services 3 months after the visit, only 0.5% of patients were up to date with all the recommended clinical preventive services. On average, 6.9 clinical preventive service discussions occurred during each wellness visit on the basis of electronic health records review, and 7.7 clinical preventive services discussions occurred on the basis of audio recordings. An average of 0.4 new diagnoses was identified, including cancer diagnoses, cardiovascular risks, and infections. Conclusions Wellness visits are an important time for patients and clinicians to discuss prevention strategies and to deliver recommended clinical preventive services, leading to the identification of previously unrecognized diagnoses. This will improve patients’ health. Policies and incentives that promote wellness visits are important, and efforts are needed to deliver them to those most in need.

Lavas from the 2021 Fagradalsfjall eruption, Iceland, show remarkable, day to month scale temporal variations in trace element and radiogenic isotopic compositions. Changes have been attributed to variation in the depth and degree of melting and/or source lithology, with progressive melting of a deeper, more enriched source as the eruption proceeded [1]. Distinguishing melting processes from source composition can be difficult to untangle using trace elements alone. Radiogenic isotopes are unaffected by the melting processes, but pinpointing lithological variations requires that the radiogenic isotopic compositions of the (unknown) endmembers are distinct and fairly restricted to be able to calculate relative contribution(s) to a lava.Stable isotopic composition may provide another perspective on the cause of the clear temporal chemical trends in the eruption. For example, it has been proposed that Fe stable isotopes may detect the contribution of distinct mantle lithologies to a lava, due to the contrasting bonding environment of Fe in mantle minerals. Both empirical and theoretical studies show that at equilibrium, pyroxenite should be enriched in heavy Fe isotopes compared to typical mantle peridotite [e.g. 2]. Due to limited ([1] Marshall et al. (2021), AGU FM Abstract [2] Williams and Bizimis (2014), EPSL, 404, 396-407 [3] Soderman et al. (2021), GCA, 318, 388-414 [4] Wang et al. (2017), GCA, 198, 151-167

Enriched mantle heterogeneities are widely considered to be generated through subduction, but the connections between specific subducted materials and the chemical signatures of mantle heterogeneities are not clearly defined. Boron is strongly isotopically fractionated at the surface and traces slab devolatilization, making it a potent tracer of previously subducted and recycled materials. Here, we present high-precision SIMS boron concentrations and isotope ratios on a comprehensive suite of quenched basaltic glasses from all neovolcanic zones in Iceland, two rhyolite glasses, and a set of primitive melt inclusions from central Iceland. Boron isotope ratios (δ11B) in Icelandic basalts and melt inclusions range from -11.6‰ to -1.0‰, averaging -4.9‰, which is higher than mid-ocean ridge basalt (MORB; δ11B = -7.1‰). Because the δ11B value of the Icelandic crust is low, the high δ11B compositions of the Icelandic lavas are not easily explained through crustal assimilation processes. Icelandic basalt glass and melt inclusion B/Ce and δ11B values correlate with trace element ratio indicators of the degree of mantle partial melting and mantle heterogeneity (e.g. Nb/Zr, La/Yb, Sm/Yb), which indicate that the boron systematics of basalts are controlled by mantle heterogeneity. Additionally, basalts with low B/Ce have high 206Pb/204Pb, further indicating mantle source control. These correlations can be used to deduce the boron systematics of the individual Icelandic mantle components. The enriched endmember within the Iceland mantle source has a high δ11B value and low B/Ce, consistent with the composition of “rehydrated” recycled oceanic crust. The depleted endmember comprises multiple distinct components with variable B/Ce, likely consisting of depleted MORB mantle and/or high 3He/4He mantle and two more minor depleted components that are consistent with recycled metasomatized mantle wedge and recycled slab gabbro.The compositions of these components place constraints on the devolatilization history of recycled oceanic crust. The high δ11B value and low B/Ce composition of the enriched component within the Iceland mantle source is inconsistent with a simple devolatilization process and suggests that the recycled oceanic crust component may have been isotopically overprinted by B-rich fluids derived from the underlying hydrated slab lithospheric mantle (i.e. “rehydration”). Further, the B/Ce and δ11B systematics of other OIBs can be used to constrain the devolatilization histories of recycled components on a global scale. Globally, most OIB B/Ce compositions suggest that recycled components have lost >99% of their boron, and their δ11B values suggest that rehydration may be a sporadic process, and not ubiquitous.

Introduction This study examines how improving curricular content and technical interface issues could make maintenance of certification activities more meaningful to American Board of Family Medicine diplomates completing Maintenance of Certification for Family Physicians (MC-FP) Program self-assessment modules (SAMs). Methods We used a sequential exploratory design to analyze quantitative and qualitative data from 320,500 surveys of family physicians who completed a SAM between January 2004 and April 2013. This included numeric rating scales and free text comments. Basic statistical rankings, template-based automated coding, and emergent coding were used to analyze SAM experience and identify thematic content. Results Across SAMs, numeric ratings were universally high and positive free text comments outnumbered negative comments two to one. When comparing feedback on the knowledge assessment and clinical simulation (CS) activities, SAMs were rated less favorably when the frequency of ideas identified by participants as most prevalent in one activity mismatched those identified as most prevalent in the companion activity. Participants were also critical of navigation issues, technical issues, and a lack of realness in the CS activity. Discussion Whether analyzed through quantitative data, qualitative data, or mixed methods, a large majority of participants rated their experience with SAMs highly. When individual SAMs were rated poorly, it seemed to be due to discordance in ideas emphasized between the knowledge assessment and CS components, or an opinion regarding the SAM topic that existed independent of the SAM process.

This dissertation ethnographically explores the contemporary phenomenon of religious apostasy (that is, rejecting ones religious faith or church community) among current and former members of the Church of Jesus Christ of Latter-day Saints (aka Mormons). Over the past decade there has been increasing awareness in both the institutional church and the popular media that growing numbers of once faithful church members are becoming dissatisfied and disenchanted with their faith. In response, throughout Utah post-Mormon and ex-Mormon communities have begun appearing offering a social community and emotional support for those transitioning out of the church. Through fifteen months of ethnographic research in the state of Utah I investigated these events as they unfolded in people’s everyday lives living in a region of the country wholly dominated by the Mormon Church’s presence. In particular, I conducted participant observation in church services, ex-Mormon support group meetings, social networks and family events, as well as in-depth interviews with current and former church members. Each chapter of this dissertation explores the causes and effects of religious disenchantment as they reverberate across multiple registers: how an overabundance of memory about Mormonism’s sacred history has led to people’s estrangement from its religious life-world; how despite rejecting beliefs on a cognitive basis the effects of those beliefs can still linger in people’s sense of embodied self; how apostates’ uncanny familiarity provokes current church members’ attempts to expel them from families and neighborhoods; and how the loss of belief is negotiated through attempts to both identity and dis-identify with the Mormon community.

A recyclable oil-based foam drilling fluid (OBFDF) system has been developed to expand the benefits of controlled pressure drilling with foam onto water sensitive formations. This paper describes chemical development and presents drilling results for a Gulf Coast well drilled with the oil-based foam system. Not only did results confirm the ability of the foam system to control fluid loss and preserve formation permeability, but also, show the advantages of drilling with foam. Furthermore, a bit trip was saved drilling the reservoir in a single bit run, with a high rate of penetration and reduced gas inflow while drilling. The OBFDF is versatile, stable at high temperature (up to 450°F), compatible with H2S scavengers and reusable. Foam properties were successfully adjusted in presence of gas and condensate inflow. Still, the flexibility of foaming, defoaming and refoaming allowed surface separation and fluids reuse. Therefore, recycling liquid make up hydrocarbon reduced fluids and chemical usage with the associated cost reduction. Onsite modeling showed the controlled pressure contractor modeling software used for water-based foams can be adjusted to properly predict drilling parameters with oil-based foams.

Human error is often related to flaws in system design which might have been avoided had greater attention been paid to human factors knowledge and methods as the system was developed. The paper considers the role of human factors in system design and argues that adopting an operational perspective in identifying human factors issues ensures that subsequent human factors advice is focused upon real needs and is consistent with how managers and engineers choose to manage their systems. It also considers the issue of timeliness of human factors input. Failure to consider human factors issues at a time when other design decisions are being taken often means that it is less straightforward to accommodate changes. Thus, managers and engineers may resist dealing effectively with potential human factors problems for reasons of cost and delay in meeting project milestones.

In recent years, the development of an increasingly capable and reliable computer technology has resulted in a trend towards the installation of computer-based information displays in the nuclear and process plant control room. The presentation of alarm information is a potentially fruitful area for the application of this technology. In the modern control room, hundreds of alarms may become active within minutes of a process transient. Unstructured, this information may be rather unintelligible to the operator, especially if he must interpret and act upon it within a short time to prevent plant shutdown. A system which is able to process and present alarms so as to minimise the cognitive demands made upon the operator and direct him towards the source of a disturbance might be expected to offer real advantages over a conventional tile-based annunciator display.